Starting sometime next year, New York will issue uniquely numbered tracking certificates for every megawatt-hour of power produced in the state or imported from other states. Each certificate will include the "attributes" of that power, such as the kind of fuel used to create it, the amount of emissions that resulted, where the electricity originated and the owner of the plant where the power originated.

Certificates can be sold, traded or used by plant owners or industry to meet government renewable-energy standards, such as New York's Renewable Portfolio Standard, which requires the state to obtain 30 percent of its power from non-polluting, renewable sources by 2015; currently, the state gets about 24 percent of its power from such sources.

The new tracking system was welcomed by clean energy advocates. "Tracking the environmental attributes of renewable energy generation will encourage a more vibrant market for green energy purchases by businesses and individuals seeking to lower their carbon footprint and help combat climate change," said Valerie Strauss, interim executive director at the Alliance for Clean Energy New York, an Albany-based lobbying group for wind, solar and alternative energy.

The state's power plant owners also see the system as beneficial. "It's important to make New York's renewable energy market as competitive as possible. Having seamless rules between multiple control areas will only promote new investment," said Gavin Donohue, president and CEO of Independent Power Producers of New York, which represents about 80 companies involved in generating electricity.

Last year, the Business Council of New York also supported the system, saying it would benefit consumers, should not be costly to implement, and have little impact on electrical rates.

Attribute tracking would also apply to power that comes into New York from other states or Canada, which each year accounts for about 15 percent of the power consumed in New York, according to the PSC.

Attribute tracking is already used by PJM Interconnection, which controls electricity in states including Delaware, Illinois, Indiana, Kentucky, Maryland, Michigan, New Jersey, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia and the District of Columbia.

According to PJM, such certificates can even benefit homeowners with solar photovoltaic (PV) systems by allowing them to report generation data and collect renewable energy credits that can be sold.